Stepladder



S. FIELD STEPLADDER July 31, 1923.

Filed Apri1,.16

. Z Z/672K671 Patented July 31, 1923.

tilTlE TTES panacea n; rain.

SJONNE FIELD, OF CHICAGO, ILLINOIS.

,. STEPLADDER.

Application filed April 16, 1921. Serial No. 461,869.

An exemplification of my invention is shown in the accompanying drawing where- Figure 1 is a side elevation of the step ladder;

Fig. 2 is an enlarged fragmentary longi tudinal section showing one of thesteps in its relation to the associated parts;

Fig. 3 is a transverse section taken on line 33 of Fig. 2; and

Fig. 4 is a fragmentary perspective showing the top step of the ladder and the fender associated therewith.

The step ladder, as a whole, follows the general structure of a wooden step ladder and comprises a step frame 10, a brace frame 11, and a top platform 12.to which the brace frame is pivoted by pivot bolts 13 in the usual manner. The special features to which the present invention is directed have to do particularly with the construction of the step frame which, on each side, is of truss formation, comprlsing a front rail 1 1 and a back rail 15, which rails,

' respectively, converge at their lower ends 16 and 16 and unite in a rounded foot 17 which is preferably shod with a rubber cap or the like to prevent slipping. The upper end 18 of the front rail is likewise inwardly bent to a slight degree, and both front and rear rails are rigidly secured at their upper ends to the platform.

The front and rear rails are of channel formation, as indicated in cross section in Fig. 3, which is a view taken through one of the front rails showing the method of uniting the same to the treads and diagonal braces. As shown in this view, the front rail 14: is outwardly bowed in its center to afford a forwardly projecting center rib 19, and is further flanged on its outer edge 20 to afford adequate reinforcement. The rear rail 15 is similarly formed, and-in the preferred construction the front and rear rails are formed of a single piece of material reversely bent at the base to afford a foot 17 adapted to be shod with a rubber cap.

The side rails serve as a mounting for a plurality of treads 21 of asizeand shape to bridge the space between the front and rear rails and of a shape to extend from one side of the step frame to the other, the general arrangement being similar to that common in the'construction of wooden step ladders. In order 'tostifien the treads, the same are provided with longitudinally extending channels or corrugations 22', three being shown for purposes of illustration. 1

The front edge of each tread is provided with a downwardly extending flange 23 which, at the points of securement to the front and rear'rails on each side of the step, is provided with a rib or channel of suitable configuration to nest into the corresponding groove or channel in the front rail.

1 Between the contiguous portions of the front rail and the tread flange is interposed the lower end 2 1' of adiagonally extending cross brace 25 whichis likewise provided with a longitudinally extending channel 26, the arrangement being one which serves to closely nest these portions of the structure,

so that a tight union can be effected by the use of a single rivet 27 which passes through three thicknesses of metal and serves to firmly secure'the treads to the front-rails on each side, and to securethe diagonal braces both tothe treads and front rails. In order ever, that the attaching end thereof is pro.

vided with a reversely bent ridge or channel 29 which is necessary in order to present the convex face thereof into nesting relation with the contiguous portion of the inwardly presented channel in the rear rail 15 of the step frame. In this instance also.

the tread is provided with a downwardly turned flange 30, the lower edge 81 of which is bent back for reinforcing purposes, and the rear tread flange 30 is likewise'grooved at the proper point to nest into the groove presented by the upper end of the diagonal brace, arivet 32 being employed for attaching purposes. In place of the rivets 27 and 32 other attaching means, such as soldering,

spot Welding, or the like may be employed for attaching the parts together.

The arrangement described is one which 7 serves to effect a very tight and rigid union between the parts composing the trontportion of the step ladder. the treads serving to properly space the front and rear rails oi .each side of the step frame, and also to proper'ly space the sides of the step frame on opposite sides of the ladder. The arrangement of the diagonal braces servesto give'a truss formation to each side of the step frame;- and this structural arrangement, to 'eth'er with maintained in distended position by means p a pivoted spreader oi the usual type. The" top platform is provided along its front. and rear edges with depending flanges 85 around which is passed a strip of cord,

rope, or-tlie 'lilieySS, which constitutes a tender to prevent marring of the alls or woodworkgthe lender being held in place by beingpassec throughstraps 37 struck out from the metal of the flange at ecurrent in-- tervals, a'sbesti indicated in Fig. It is obviousthat the details t the ladder structure'may be modified to a 'reater or less degree Without departing from the spirit or the invention.

I claim-r 1. In ainetallie step ladder, the combination of a frame consisting on each side of a front and a rear rail each formed of sheet metal to provide an inwardly opening channe'l,-a plurality of sheet metal treads having downwardly extending vertical flanges at their front and rear edges each flange being provided at each end With an outwardly bulging rib nested into the channel in the adj ace'nt frame rail, and attaching means for their front and rear edges ,'each flange being provided at each end wvith an outwardly bulging rib'nested into the channel in the adjacent frame-rail a plurality of diagonally extending braces for each pair of frame rails, each brace being of open channel formation and configured at each end to furnish anoutvvardly bulging rib nested between the adjacent rib of a tread and the rail channel and attaching means extending through the tread-flange-rib, the brace end and the frame rail at each point of contact or saidelements substantially as described.

3. In a metallic step ladder, the combinationo'f a frame consisting on each side of a front and a rear rail, each formed of sheet vertical flanges at metal to provide an inwardly opening channel', a plurality of sheet metal treads having downwardly extending vertical flanges at their front and rear edges, each fiange'be ing provided at each end with an outwardly bulging rib nested into the channel in the.

adjacent frame rail; a plurality of diagonally eigtending braces for each pair of frame rails, each brace being of open channel formation and configured at each end to furnish an outwardly bulgingrrib nested'be tween the adjacent rib of a tread and-the railchannel, andattaching' means extending through the treadflangerib, the brace end and the frame rail at each point of con tact of said elements, the lower ends ofeach pair of rails being converged and united to Iorm a foot, substantially as'described.

, sJoNNE FIELD,

Witness: l V

EPHBAIM B'ANNING. 

